This invention relates to a container for packaging a medicine, and more particularly to a container which has a moisture proof and can absorb odoriferous ingredient emitted from a medicine accommodated therein to prevent foul or offensive odor from being emitted outside of the container.
In medicines generally used, especially oral medicines, a property of being easily soluble in water (a high water solubility) is given to them in view of necessity for dissolving them in a stomach, and a moisture proof is required for a container for such medicines.
If the container for the medicines does not have a sufficient moisture proof, moisture in the air passes through the container for medicines to enter the container and to react on the medicines accommodated therein to cause discloration of the medicines and decrease of effect of the medicines.
Press Throught Packaging (PTP) is, at present, mainly used for packaging medicines because of economy due to its compactness and facility of use by patients.
A container obtained by PTP comprises a plastic sheet having a medicine accommodating portion and an aluminum foil sheet which is attached to the plastic sheet in a manner to cover the medicine accommodating portion of the plastic sheet. With respect to medicines for which a high moisture proof is not so required, a polyvinyl chloride sheet is used. With respect to medicines for which a moisture proof is required, a polyvinylidene chloride coating polyvinyl chloride sheet is used.
Among medicines accommodated in PTP container, some medicines emit carbonic acid gas, hydrogen sulfide gas, trimethylacetic acid gas and the like. Carbonic gas emitted from medicines is odorless, and hydrogen sulfide gas and trimethylacetic acid gas emit offensive odor, respectively.
In a plastic sheet, including vinyl chloride, for a PTP container, a gas permeable resistance is relatively high, and a moisture proof is, however, low to cause medicines accommodated in the container to react on moisture whereby the medicines are discolored and effect of medicines are decreased.
In a plastic sheet, including polyvinylidene chloride coating polyvinyl chloride, for a PTP container, a moisture proof is high, and however a gas permeable resisitance is not high. Therefore, in case that medicines emitting gas are eneveloped in the container, gas emitted from the medicines cannot easily pass through the plastic sheet, and the inner pressure of the medicine accommodating portion is increased. Resultantly, there may be a case wherein a seal portion is broken due to expansion of the medicine accommodating portion.
In a plastic sheet, including polypropylene, for a PTP container, a moisture proof and a gas permeability are high to overcome the above problems. However, since the plastic sheet including polypropylene has a good gas permeability, in case that hydrogen sulfide gas or trimethylacetic acid gas is emitted from medicines enveloped in the container, offensive or foul odor is emitted near a place where the medicines are stored to influence environment badly and to give an unpleasant feeling to patients.